J. Falbe, "New Syntheses with Carbon Monoxide", Springer Verlag, Berlin Heidelberg New York, 1980 reviews known carbonylation processes for the preparation of amides. In the known processes, generally an acetylene or olefin is reacted with carbon monoxide and an amine or amide in the presence of a carbonylation catalyst. The carbonylation catalyst typically comprises a source of a Group VIII metal. Several of the carbonylation catalysts also comprise a ligand, for example pyridine or a phosphine.
British Pat. No. GB 2,216,036 discloses a process for the carbo-amination or carbo-amidation of olefins, which process comprises contacting an olefinically unsaturated compound in the liquid phase with carbon monoxide or a carbon monoxide-containing fluid and a compound having the structure H--NR.sup.1 R.sup.2, wherein R.sup.1 and R.sup.2 are each independently selected from hydrogen, a hydrocarbon group or a group --C(O)--R.sup.3, in which R.sup.3 independently may be hydrogen or a hydrocarbon group, or R.sup.1 and R.sup.2, together with the nitrogen atom to which they are attached, form a heterocyclic group, the hydrocarbon moieties R.sup.1, R.sup.2 and/or R.sup.3 optionally containing as further reactive groups one or more primary or secondary amino and/or aminocarbonyl groups, in the presence of a catalyst system obtainable by combining:
component (a):--a ruthenium compound, and PA0 component (b):--a compound having an anion of an acid with pKa value &lt;3.5 (measured at 25.degree. C. in aqueous solution).
The reaction rates reported in the Examples in GB Pat. No. 2,216,036 are in general low.
It has now been found that amides can be prepared at a good reaction rate using a carbonylation catalyst which comprises a particular nitrogen-containing phosphine ligand.